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Functions Defined by Data

Part 1: First Class Postage Rates

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The following table lists first class postage rates (in cents), with each rate paired with the year in which it took effect. The time frame for this data is more than a century. (Source of data: Associated Press, 7/2/97.)

stamp
Year Postage
(cents)
Year Postage
(cents)
1885 2 1976 13
1918 3 1978 15
1919 2 1981 18
1932 3 1982 20
1958 4 1985 22
1963 5 1988 25
1968 6 1991 29
1971 8 1995 32
1974 10 1999 33
  1. The worksheet you downloaded to start your computer algebra system contains a command for defining a list of data points that match the data in the table above. Enter the command to construct the list of data points.
  2. Next you will find a command for making a scatter plot of the data. Enter that command, and experiment with any plot options you find in the worksheet.
  3. In your worksheet, write a brief description of what you learn from the graph about postage costs in the United States. One or two complete sentences should suffice.
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